Tire mold



June 16, 1925.

T. MIDGLEY TIRE M oLD original Filed March 2, 19.25`

INVENTOR. fym BY TORNEY.

Petenred June 16, 1925.

UNITED STATE-s 'menus nmoL'nY, or HAMPDEN;

PATENT FFICE.

MASSACHUSETTS, ASSIGNOR TO THE FISK 'RUBBER COMPANY, 0F CEICOPEE FALLS, MASSACHUSETTS, A CORPORATION OF MASSA- CHUBETTS'.

TIRE MoLn.

Application led Iarch 2, 1 923, Serial.

To all whom t may concern:

`Be it. known that I THOMAS MIDGLEY, a Citizen of the United states of Ameriee, residing at Hampden, in the county of Hampden and State of Massachusetts, have .invented certain new and useful Improvements in Tire Molds, of which the followin is a specification.

e present invention relates to improvey ments :in molds adapted for vulcanizing rubber articles such, for example, as tirecasings, and is particularly directed to the'imbe formed endless. The mol provement of such molds in economy of operation, low cost, and lightness.- It .finds particular utility with molds intended to be used under internal pressure., r v

The invention will now be described in connection with the accompanying drawin s, in which ig. 1 is a sectional view of a mold con'- structed in accordance with myinvention;

and

Fig. 2 is a view thereof with the partsl separated.

In copending applications Serial. Nos. 621,425, filed Feb. 26, 1923, and 622,491, filed March 3, 1923, I have described molds having certain features in common with that described herein. I have claimed such common or generic features in those applications, the present case being directedto certain modifications which will now be considered.

vThe mold as shown in the specific embodiment illustrated has an-annular base rtion 10 split as shown at 11, the split being closed by a Wedge 12 suitably dovetailed or beveled to make a ti ht and stable fit. lThe mold has also a treat? ring 13, which may be engraved or otherwise formed at 1'4to impress upon the tire to be vulcanized the def sired pattern. This piece ma conveniently also has side plates 15, suitably formed tok the configuration of the tire. These plates yare preferabl sheet steelstampings, smoothed and bu ed if necessary on their inner surface to give a smooth appearance tothe tire. The inner edges of the plates fit in grooves 16 in the base ring 10, and their outer edges t against shoulders 17 on the tread ring, where they are held in place by snap rings 18 fitting in grooves 19 in the tread ring. Wed 12 is formed with a continuation gf t e grooves 16. The snap rings may` con- 1re-622,264. Renewed april 27, 1925.

bag the base portion may be left :dat transversely, or ii; may beA recessed at 22 to re' ceive thevbase of the bag. The latter oonstructlon 1s preferable, as the lpressure ex- To receive this c rted by the bag against the beadsv of the t1re is more uniform. The outer'edges of the side plates are preferably bent as at 23 .I

to give space for the removal of the snap rings.

` A mold so` constructed is vreadily asseml bled and disassembled. have been vulcanized in moved as follows.

Assuming a tirato the mold, it is re-l By. drivingl out wedge l2 the base ring can be collapsed suiciently to free its grooves 16 from the edges of the side plates, 4and can thenbe withdrawn laterally. One or both of the snap rings 18 being sprung out of their retaining grooves, one or both, as the casemay be, of the side plates can be removed from the tread ring. The tire may nowbe pried free of the tread ring and removed. The operation of assembly is conducted in a reverse manner.

A mold so constructed has numerous advantages over molds of previous types. In the first place itcan be made p'artially or entirely of rolled, pressed, or forged sheet steel, permittingv a great decrease in the weight of the assembled mold. This is of importance not only in ease of handling and cost, in which features it far surpasses molds now in use, but also in the saving of steam or other heating means. during' vulcanizaber goods it is `of course necessary to heat the mold along with the rubber, and to C001 oii the mold to permit handling after the vulcanization has been completed. The heat used in bringing the metal of the mold to the tem rature of vulcanization is wasted, and 1s eliminated lby the present invention to the extent that the amount of metal is reduced.

Having thus described my invention, I claim:

1. A mold for the vulcanization of tire casings having a split vhase ring,

a wedge joining the ends of such ring,

a tread ring 95 tion. In ythevulcanization of molded rubv formed to the pattern of the tread portion of the tire, a pair of side plates ittin .at their inner edges into grooves in the.. ase ring and wedge and at their outer edges against shoulders on the tread ring, and snap rings tting into grooves in the tread ring and serving tohold the Side plates against the shoulders, whereby arigid assembly of all the recited parts is produced.

2. A mold for the vulcanization of tire casings comprising a split base ring having circumferential grooves therein, a wedge -joining the endso such ring', atr'ead ring,

apair of'pressedsteel side plates fitting into the grooves, and ,means for holding the side plates in position relative to the tread ring. 3, A mold. for the vulcanization of tire casngs comprising a, base ring transversely "split 'and having circumferential grooves therein, a pair of side plates of substantially uniform thickness adapted. to t into said grooves, means for holding the base ring lin engagement with the side plates, a tread ring, and means for holding; the 4side plates 'inengagelnent with the tread ring.

THOMAS MIDGLEY. 

